hi, got a bit of rot on a disco ali body panel and its anodising white powder best treatment to stop that please, thanks in advance for your responses

thanks for your input

first of all I have an odd disco1 300tdi, it is a 3 door registered in 2000 put together in 1999 in Solihull from the info I found on the vin plate, now then rear pads (mintex) fitted seem to be slipping down through the callipers and wearing a groove in the disc, any input would be good, thanks